code: def setUp(self):
      self.children = [HTML("0"), HTML("1")]
      self.widget = Accordion
  
imports: from unittest import TestCase
  from traitlets import TraitError
  from ipywidgets.widgets import Accordion, Tab, Stack, HTML
label_desc: Use image node_id 1 for calling the TestAccordion obj's underlying member method code with example usage: obj.setUp() without return types